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Rare earth isovalerates and their mixed-ligands complexes with amines as precursors for chemical deposition of mixed-oxide thin filmsтезисы доклада
- Авторы: Tsymbarenko D., Kendin M.
- Сборник: 27th International Chugaev Conference on Coordination Chemistry and 4th Young Conference School "Physicochemical Methods in the Chemistry of Coordination Compounds". Book of Abstracts
- Тезисы
- Год издания: 2017
- Место издания: Типография ННГУ им. Н.И. Лобачевского Nizhny Novgorod
- Первая страница: P65
- Последняя страница: P65
- Аннотация: Since the rare earth (RE) complex oxides in a form of thin films have a huge number of application as functional materials the development of chemical solution deposition method (MOCSD) of such thin films is currently under high interest. Mixed-ligand complexes of RE carboxylates with amines are considered as promising metal-organic precursors. Here we present synthesis, composition, structure and thermal behaviour of RE isovalerates and their mixed-ligand complexes with monoethanolamine (MEA) and diethylenetriamine (DETA). RE isovalerate hydrates of general formula [Ln(iVal3)(H2O)n] (Ln = La, Gd, Y, Lu; x = 0-2) were synthesized for the first time by 4 methods based on ligand-exchange reactions in water and organic solvents. The composition of products was studied by TGA, IR and XRD methods. Syntheses in water solutions give high yields for light RE (La-Gd), whereas reactions in organic solvents give higher yields for Y and heavy lanthanides. A new crystalline structure of [Gd(iVal)3(H2O)2]2 has been detemined by XRD. The unit cell contains two centrosymmetric dimers, formed with two chelate-bridging iVal-ligands and containing two 9-fold coordinated Gd ions. RE isovalerates have reacted with MEA and DETA forming hydroxogels, except La. Hydroxogels decompose in air at temperatures as low as 600oC forming RE oxides that allows their application as solution precursors for MOCSD. Solid crystalline complex [La(MEA)(iVal)3] has been obtained and it also seems to have typical dimeric structure which was modeled by DFT calculations. Deposition of Y2O3, LaAlO3, LaLuO3 thin films were performed as follows. RE isovalerates were dissolved in isopropanol with the excess of DETA to achieve the resulting concentration of 0.2-0.3M. Obtained solutions were used for chemical deposition on single crystalline (SrTiO3 (100) and YSZ (111)) and polycrystalline (hastelloy) substrates and heat treated at 150 and 550°C. Deposited films were characterized by XRD and AFM. The presented metal-organic precursors were successfully applied for deposition of both amorphous/nanocrystalline and crystalline textured films. For example, obtained Y2O3/Hastelloy films have average roughness of 0.8 nm which is perfect for smoothing layers. On the other hand, annealing of as-deposited mixed-oxide films at 1000oC results in formation of crystalline oriented films (LaLuO3(100)/STO(100) or LaLuO3(110)/YSZ(111)). Therefore, developed metal-organic precursors show good results in deposition of RE mixed-oxide films. Furthermore, solutions of RE isovalerate amine complexes are compatible with solution of transition metal ones. This fact allows to use the developed precursors for deposition of RE and transition metal mixed-oxide films (RE ferrites, manganites, nickelates, etc.)
- Добавил в систему: Кендин Михаил Павлович